Dovecot cannot start at boot

Dovecot cannot start at boot. Mail log shows this error after boot:

Code:

# tail -f /var/log/mail.log
Jun 19 10:09:53 host postfix/smtpd[3126]: warning: SASL: Connect to private/auth failed: Connection refused
Jun 19 10:09:53 host postfix/smtpd[3126]: fatal: no SASL authentication mechanisms
Jun 19 10:09:54 host postfix/master[2224]: warning: process /usr/lib/postfix/smtpd pid 3126 exit status 1
Jun 19 10:09:54 host postfix/master[2224]: warning: /usr/lib/postfix/smtpd: bad command startup -- throttling

emails cannot be delivered, and I'm forced to restart Dovecot manually: #service dovecot restart , and then it works.

Just I have tried a dovecot update preserving my configuration. Maybe some unexpected change?
I'm with Debian Jessie

Some idea why it happens?.

 

yes
I can start manually. This is the status of dovecot (after start manually):

Code:

# systemctl -l status dovecot
? dovecot.service - Dovecot IMAP/POP3 email server
   Loaded: loaded (/lib/systemd/system/dovecot.service; disabled)
   Active: active (running) since mar 2018-06-19 11:45:26 CEST; 28min ago
 Main PID: 3585 (dovecot)
   CGroup: /system.slice/dovecot.service
           +-3585 /usr/sbin/dovecot -F
           +-3587 dovecot/anvil
           +-3588 dovecot/log
           +-3590 dovecot/config
           +-3595 dovecot/auth
           +-6183 dovecot/ssl-params

jun 19 12:12:24 host.myhost.com dovecot[3588]: pop3-login:....

thanks for the help

Is this a systemd issue?

 

oh... I have checked the services before with sysv-rc-conf and 2,3,4,5 were active for dovecot. It was useless I suposse.

After doing #systemctl enable dovecot.service error is finished and problem solved

thank you!